LilKim wrote:This is something that i've always asked.. what's the correlation between animal body size and life expectancy.

For example: ... a Chihuaua is expected to have a life span that is 2 times longer than great dane.

Why is that?

The generalization is hard to do as the body size is not mostly the so called ' natural variable' for the life expectancy function.
Sorry that was all dry words. But i mean moslt life span doesn't directly get affected by the body size but it does affect in several ways
for some targets of carnivores, big body size is just hell! There its the natural variable. A rare example.
I don't know grat dane & the chihuaua! Tella.

just a theory, but maybe the years of breeding that went into creating the Great Dane came up with an animal that was built in a way that puts a lot of stress on its heart and joints. The Chihuahua on the other hand spent a lot of time in a culture which may or may not have been as carefull about breeding, and thus have produced a dog with greater genetic variabilty.

123Herpatology wrote:2 years give or take...i've never hears of any solid research that says great danes have a lower life expectancies than chahuahua's.

The fact that small breads live longer than large breeds is a well know/established fact that is unquestioned by breeders and dog veterinarians. It's even published as a counter example to the new formula on size, life expectancy of all animals. Doing a controlled study to prove a well know fact would be expensive and uninformative.

I found this post searching for an answer to the question why do Male Orcas (twice the size of females) have half the life expectancy (I was wondering if the dog/size phenonoma was at work). That's my real question. I guess a follow up is why do small breeds live longer than large?

while it may be true that smaller "breed" dogs live longer than larger breed dogs, mixed breed dogs live as long or longer (13.5) , and so size can not be the only factor.

Elephant life espectancy is about 60 years, and a Chihuahua lives about 13. I know that studies have shown that overeating reduces life span in animals.

My conclusion is with dogs, is that the life expectancy has more to do with mutations which limit the life span of the species.
~Lynne

"How far you go in life depends on your being tender with the young, compassionate with the aged, sympathetic with the striving and tolerant of the weak and strong. Because someday in life you will have been all of these".

Linn wrote:while it may be true that smaller "breed" dogs live longer than larger breed dogs, mixed breed dogs live as long or longer (13.5) , and so size can not be the only factor.

I know that studies have shown that overeating reduces life span in animals.

My conclusion is with dogs, is that the life expectancy has more to do with mutations which limit the life span of the species.~Lynne

You should not interpret breed to be pure breed. The trend of size/life expectancy is exceptionally linear across mutts too. Yes, mutts tend to live longer than pure [in]breeds of the same size.

A 1/4 Shepherd, 1/4 Rottweiler, 1/4 Lab, 1/4 golden would be considered a large breed. In general it would have a longer life span than any of the individual [in]breeds.

>> overeating reduces life span Yes, so does stress, poor diet and many other factors. These variables apply to all dog sizes.

>>Elephant life [sic]espectancy is about 60 years, and a Chihuahua lives about 13Irrelevant to the question of size/life expectancy of a species. I've provided a citation which supports the well know fact. Ask any vet who cares for canines, the correlation is well know/established and not questioned by experts in the field.

Linn wrote:while it may be true that smaller "breed" dogs live longer than larger breed dogs, mixed breed dogs live as long or longer (13.5) , and so size can not be the only factor.

I know that studies have shown that overeating reduces life span in animals.

My conclusion is with dogs, is that the life expectancy has more to do with mutations which limit the life span of the species.~Lynne

You should not interpret breed to be pure breed. The trend of size/life expectancy is exceptionally linear across mutts too. Yes, mutts tend to live longer than pure [in]breeds of the same size.

A 1/4 Shepherd, 1/4 Rottweiler, 1/4 Lab, 1/4 golden would be considered a large breed. In general it would have a longer life span than any of the individual [in]breeds.

>> overeating reduces life span Yes, so does stress, poor diet and many other factors. These variables apply to all dog sizes.

>>Elephant life [sic]espectancy is about 60 years, and a Chihuahua lives about 13Irrelevant to the question of size/life expectancy of a species. I've provided a citation which supports the well know fact. Ask any vet who cares for canines, the correlation is well know/established and not questioned by experts in the field.

I used the example of the elephant, (which is relevant to the discussion ) to show that it is not size that is the reason for shorter life in animals in general. and very small animals live shorter lives.

I maintain its NOT the size that leads to a long life.

The dog I have now (medium size) is 17 years old pure breed. (he has the Chihuahua beat by four years so far!

before him I had a german shepherd/collie/lab mix lived 18 years.

"How far you go in life depends on your being tender with the young, compassionate with the aged, sympathetic with the striving and tolerant of the weak and strong. Because someday in life you will have been all of these".

I don't think so. We both agree there is a very good positive correlation between animal size and life expectancy across species.

But for dogs and whales (within each species) to correlation is inverse, ie Larger whales have shorter lives and larger dogs have shorter life expectancies.

>>The dog I have now (medium size) is 17 years old pure breed. (he has the Chihuahua beat by four years so far!

You must take really good care of that dog (good for you). But anecdotes are worse than useless in science.

>> german shepherd/collie/lab mix lived 18 years.
I'll bet that dog was smart (shepherd/collie mutts have been known to do calculus

I still need to find out why the larger male Orcas are twice as big as the females and live half as long. The environmental (with no-science) extremist on my Orcas trip said it was because the females give birth. I doubt and shed toxins. I doubt that's the reason.